Welcome to the XRAY T4'16 Thread & Wikipost! Here you will find some useful info, tips and tricks as well as setups that are used by several team drivers. This wikipost is a work in progress and should continue to develop over time.

New Graphite Hubs:
Xray have recently released some additional Graphite hubs for the T4 lineup. The 4° Graphite C-Hub has been out for some time and is known to improve steering on entry, and in general makes the car turn better. This has been the go-to c-hub on asphalt for many on the Xray team, though it is not needed on high bite carpet. The Graphite rear hub tends to make the car more stable, especially on corner entry. We are still working on gathering input on the new Graphite steering block, but for the moment feel that it should improve steering response. All Graphite parts are approximately 1g lighter than the Hard or Medium options.

No I understand that but I've been noticing more of the team drivers running the aluminum C-Hubs for the ARS set-up and wondered why or what that gives you

I've been told that alum chubs on ARS can give more consistent rear grip than the composite. Specially Outdoor racing with hot temperature can make composite ars chub become "softer" that can hurt the rear grip

I'm almost done building my T4 (a 2015 version which I got unbuilt) and thought I would share my impressions. Once again I find myself agreeing with Lonestar : Xray t4'15

Hinge pins : They are not absolutely straight. Not to the point where you would consider replacing them, but still not perfect. In the process of polishing them, in chucked them in my dremel and in a few cases you could feel quite a little vibration. The chuck of my dremel is not at fault because the hinge pins from my previous car (T.O.P.) spin dead true every time.

Screws : first off there are several brands/types of screws depending on the step of the build, even though they are of the same dimensions. For instance the M3x6 screws for hinge pin hangers are different from the M3x6 screws they give you to attach the bulkheads. When you look at the underside of the car, you clearly see that there are several types of screws. I find it annoying. Was is so hard to choose one type ? Now if you are the slightliest bit of a perfectionist (as most of us are, I suppose) you have to pay attention to which screw goes where when wrenching on the car. Just silly.

A second issue with screws is their length : they are too short in quite a few places. Shock towers, hinge pin hangers, bellcrank bridge come to mind. So again I tried to swap them where I could, which is not easy if you don't have Xray screws laying around (for example, the button heads have this small cone under the head that I wanted to keep.)

One last issue with screws : Some of the button heads had the head visibly out-of-round, which bothers me to no end. When you screw them to attach the top deck you just know it's going to be prone to tweaking. VERY annoying.

That said, the steel from the screws seems hard and they feel good when you tighten them down, assuming you have good hex tools.

A-arms hangers : The rear split blocks are not marked for orientation. I assume they can be mounted on either side, but when you look at the square hole where the plastic pill goes, the chamfers are not quite of the same depth from one side to the other. So it had me wondering from which side I should insert the pill. Not a huge deal, but definitely something I could have done without.

Rear hub carriers : there is 0.15mm of axial play on the outer hinge pin. Nothing a shim can't take care of, but again I could have done without it. Additionally, I would have liked to get two M3x4 set screws to put in the unused camberlink hole. Everyone knows you have to do this, was is so hard to include those two set screws in the box ? Also, why not include crush tubes between the wheel bearings ? I had to buy some from a 3rd party.

The diff : it builds okay but the outdrives are quite bound up by the O-rings. Plus, there remains a bit of grittiness/notchiness when it's closed, although I am pretty sure it will go away after running the car. Still, not perfect. (Yes, I know how to build a diff properly, thank you.)

Servo mount : why is it not perfectly centered ? I don't think it hinders the handling to have it offset by a millimeter or two (after all even the asymmetric steering geometry on the T1 was never a problem), but it makes the thing look like and afterthought. Also, I would have liked the outer servo post to be keyed, so that it would be pefectly straight.

Ball studs : again, they are too short for my liking, in quite a few places. This is even more worrying than screws, for obvious reasons.

Bumper : they give you this little plastic bit that screws on top and prevents the front of the chassis from cracking under impact. Was in so hard to mold it in a way that the marks from the moulding were hidden ? I don't mind too much that the thing looks like an afterthough (which it is, of course), but the three shiny circles right on the upper face of the part ? Please ! Better yet, just mould a new damn top bumper plate that includes that small piece of plastic, shows the xray logo as it was supposed to, and uses two countersunk screws instead of the button heads. Regarding the foam itself, it is too soft for my liking, but it is very light as well, so I am willing to let that pass.

The manual : it is not perfectly clear at times. For instance I had to look at the picture on the cover to take a guess at the orientation of the orange part of the servo mount. It would also help if the manual wasn't so encumbered by the advertising of options parts, in-between build steps. Why not put all of this stuff at the end ? All in all, still a pretty good manual, but not great.

I have yet to build the shocks or the turnbuckles, so I will refrain from commenting.

Belt tensioner, plastic outdrives, plastic wheelbase shims : I put these in the same category since they are features which I knew of before buying the car ; so I can't really complain and act disappointed. But still, as I was progressing through the build, these little things ended up bothering me because they felt so cheap. Who buys a TC which says « luxury » on the box and is okay with petty things like plastic shims off a tree ? NOT ME. And yes, I know that spring steel outdrives cost more (DUH) but who is going to run the car with the plastic ones ? Anyone knows that they are going to get notched by the bone pin and deteriorate the car's handling within a few runs. My FK05 came with the spring steel outdrives and now they are a hop-up ? PLEASE ! And no belt tensioner ? Even with a slow motor the belt flaps around without a tensioner. It costs the manufacturer next to nothing. Was it so hard ?

To sum up, the Xray is still a good car as far as quality goes, but it certainly has lost its « near perfection » status in my eyes. If you want to market your product as « luxury », I am afraid you will have to step up and actually EARN your spot at the top again !

Nearly all points you mention won't hurt the performance at all (exept for the button head screws...).
I will not defend Xray. Unfortunately this company is on the same path like most of the others. Quality costs money and so they just look how to optimize their income and buy cheap (the screws maybe come from different producers to buy as cheap as possible) what the don't produce. What they produce is calculated in time. So no one cares if the chamfer looks the same after the part was turned around by the cnc maschine (or however they do it).
The plastic shims in my opinion do the job well on the hinge pins. I don't want to use them on the inner camberlink ballstuds, but use them on the steering arm and c-hub. No problem at all.
The term "luxury" is of course pure marketing and depends on what car you are coming from. Quality has nothing to do with it in our times. That is lame I know.

I also have to say that my '15 doesn't have your mentioned issues. My screws are ok, I don't have the play in the carriers, the servo mount sits correct...

Things which I don't like are the swelling bladders and diff seals. And of course the price for some tuning parts like the PSS...

Xray gear diffs are the gold standard in on road, if it's notchy you could've missed some flashing, regardles it will smooth out. Did you use grease on the o rings and outdrives? I personally use avid slop on the o rings and grease on the outdrives. The orange portion of the servo mount can be installed either way, one way allows you to insert a bolt and a few shims to use as a battery stop. The ball stud lengths have never caused any issues for me, or anyone else that I'm aware of. Belt tensioner is an unnecessary part and you'll see that almost no one runs one on a t4. The plastic spool cups are not ideal, but they do work fine in stock classes. They will wear and cause binding, which will warrant their replacement. The new rsd spool cups are top notch and are what I'm running in mod. While I do use aluminum shims throughout my sedans, I've never had any issues with the plastic ones, in fact I'm using them on both of my xb2s with no issues.